syscalls/readahead02: use bdi max readahead limit

After commit 600e19afc5f8a6 ("mm: use only per-device readahead limit")
readahead size is not limited anymore by 2 megabytes. Instead,
the per-bdi limit is used for kernels 4.4 and older.

Signed-off-by: Roman Gushchin <klamm@yandex-team.ru>
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
1 file changed